XW8600 Memory Riser Questions

There are a few topics concerning the risers on this forum and they have been helpful however I have a few additional questions.

I recently acquired a riser assembly with 32GB of memory (16 x 2GB) for a good price. I had to locate a power cable assembly and am waiting on that to arrive. The price of the two is still far less than 8 X 4GB memory modules. Far less so that is a plus.

I have the 1050 watt power supply.

I do NOT have the high performance (tall) heatsinks nor do I have the fan duct that is supposed to be installed with this.

I am wondering if it'll be OK to run with what I have, heat-wise. I suppose I could zip-tie a fan to the side of the riser cage, a little hokey, but if that'll work it's better than spending the money it would take to procure the tall heatsinks. There is already a fan on the existing 8 x 2GB memory modules so I suppose I could re-locate that via the aforementioned zip-tie method.

Re: XW8600 Memory Riser Questions

Some time ago I posted here on getting the "double tall" heatsink/fans figured out in terms of its wiring and how the motherboard knows it has one of those installed, with 2 fans, and thus lets the workstation function with greater than or equal to 120W Max TDP processors. If the xw8600 senses it has such a processor then it wants to see that type of heatsink/fans combo, and will give an error message if it does not. My project had to do with getting one of those xw8600 double talls converted to the wiring used in the xw8400, which did not have double-tall heatsinks. The wiring understanding allows one to reverse engineer a single tall to mimic a double tall.

I'm guessing you may have a similar issue with the riser(s). The motherboard may refuse to cooperate if you don't have the right heatsink/fans attached to the motherboard.

I mention in the posts exactly what the wiring is for the 5-pin plug for that type of heatsink and how the two fans feed into that. I also mentioned how one could spoof the motherboard by a little wiring trick, and use a single tall heatsink/1 fan but wired as if there were two fans. If you're not going to push that xw8600 hard then you could get away with this spoof, I believe. Or, buy the double-tall one(s) for your project at a minimum of about 90.00 each off eBay.

I'm finding 4GB used HP sticks for pretty cheap recently on eBay.... as low as 6 for $90.00. Overall it might be cheaper to go 8 x 4 = 32GB.

Re: XW8600 Memory Riser Questions

Some added info for other budget conscious xw workstation experimenters here who might be hearing about a degree of price drop in the 4GB sticks for the first time, used, off eBay is provided below. One of the reasons for the good prices is that there was quite a bit of memory/processor cross over from the xw workstations to HP servers of the same time period. Enterprises have been updating their HP workstations and servers simultaneously. I think there is less of a used market for the servers than the workstations, and hence the used server memory and processors are available with excellent supply now for those of us recycling the xw workstations.

First, I like HP-labeled memory the best.... it has been binned to high level specifications, and intermixing the HP-labeled sticks from different OEM vendors seems to work the best, if necessary. I have seen timing issues when intermixing non-HP memory.

Second, if you can get all your HP-labeled sticks from the same vendor source that is the best way to go. The same HP part numbers can be on multiple vendor's sticks.... Micron (blue heat spreader), Elpida (black), Nanya (black), Samsung (silver) and Hynix (gold). I have had some problems with the 4GB Micron blues, and like the Elpida and Nanya quite a bit for the 4GB sticks. When I probed the Micron blues in 2GB form they had Micron chips, but at least some of the 4GB Micron sticks did not. That might explain some of the issues I saw. I like the HP Micron blues for 2GB sticks.

Third, it still is cheaper per GB to buy 2GB sticks, but when you can find a 4GB HP stick for $15.00 USD each stick then you're truly getting into a range that is justifiable. The xw6400 only has 4 memory slots..... that is a workstation where those on a tight budget might want to strongly consider 2 4GB sticks initially, and add more in the future if needed for 64-bit operating systems.

Fourth, I have posted here in the past the different HP part numbers for 2GB and 4GB sticks.... the numbering system can get confusing due to kits of 2 sticks each, option part numbers, assembly numbers, spares numbers, workstation versus server numbers..... A good thing to know is that the same HP sticks seem to work perfectly in the xw6400, 8400, 6600, 8600. Also, there are server and workstation versions of these sticks that in my experience function and intermix perfectly, with part numbers differing only by end modifier..... -051 and -551 work equally well in 2GB sticks (398707-051 and 398707-551). -061 and -661 work equally well in 4GB sticks (398708-061 and 398708-661).

Fifth, you may see an automatic ramp-up in speed of fans with the addition of more RAM. I have seen that with at least some xw6400s when they receive 16GB. I have not seen that with the xw6600 at 16GB. I have not experimented with this in detail, and for our teleradiology work we have found 8GB is an excellent amount of RAM. If I add in 3D image reformation software, however, I'd go with 16GB in a xw6600 and 12GB in a xw6400.

Re: XW8600 Memory Riser Questions

Thanks for the info, Scott. I purchased what the sellar guaranteed was HP labelled memory but could not guarantee which brand but they did say it could be one of the exact ones you mentioned. The specs matched up and I don't anticipate any issues.